Last night I spent quite a bit of time tidying my house. Tonight after getting back from my walk I sat down at the PC to check my email and looked around. There is a bag of clothes I use for exercising, the clothes I changed out of, and some paper work I displaced to sit down at my PC. The tidiness of my room has been eroded. Now if I don't do something about it I am likely to make more mess, in small ways until the place is really screwed. At which point why bother worrying about the small things given the overall state! Chaos ensues!
Weight gain is like this I think. Most people, fat or thin eat about the right amount of calories most of the time, if not the thin people would starve to death and the fat ones balloon and explode. Of course there are examples of both of these things (just a wafer thin mint?) but they are the exception not the rule. People generally put on weight in little chunks, a Christmas here and a stressful week at work there. It is very easy to overeat occasionally and you tend to get some pleasure from it, on the other hand to create a calorie deficit is not normally a pleasurable experience (except for fun sports/activities) and certainly more difficult to do by accident. We also tend to compensate for exercise with more food levelling our selves out, on the other hand too much food makes us sleepy!
This is just like my untidy house. It becomes a real mess not by constant mess making but by a set of small events that require little effort and are often the result of some other action that was very possibly pleasurable (or at least I was motivated enough to do.)
So what is the key? I guess it would be to tidy little and often, to offset the mess making events or to not make a mess at all and if the place is such a s^&t hole that it is too much to face at once then it could be completed by lots of little tidying events.
Similarly for weight control, you can try to avoid weight gain events to start with or you can counter act them with weight loss events like exercise or lighter meals. And if you have a lot of weight to lose then you again tackle it with a lot of small steps. This is another reason why perfection is less important than persistence, if you tidy up more than you make a mess your place will get tidy regardless of the fact you left an empty glass on the table because you could not be bothered to take it down to the kitchen (it is a long way.) And for weight, if you have more positive weight related events than negative then you will surely achieve your goals in the end.
This is another argument for separating yourself from temptation as it is a cause of weight gain events. It is also a reason to think about your means of weight loss, you want to make it enjoyable and maintainable because you are pitting the events against each other. Which will win, a cheeky cream cake or a 6am run in the park?